In this kind of fanfiction, Naruto being heartbroken by Rias could be due to a variety of reasons. Maybe Rias betrays Naruto in some way, like choosing someone else over him in a crucial situation. Or perhaps there are misunderstandings between them that lead to Naruto's heartbreak. It could also be that Rias has to follow some rules in her world that go against Naruto's expectations, causing their relationship to shatter.
One aspect could be that the fanfiction shows Naruto's heartbreak in a very visual and emotional way. For example, he might see his parents in a dream - like state and then they disappear, leaving him feeling more alone than ever. It's a way to dig deeper into his character's vulnerability, which was somewhat masked in the original series by his determination.
Self - discovery is also a theme. Through the heartbreak, Aang has to reevaluate who he is and what he wants. He may question his purpose as the Avatar or his ability to love. This can lead to him growing and changing in unexpected ways in the fanfiction.
A possible 'Harry heartbroken fanfiction' plot is when Harry discovers that Ginny has been secretly dating someone else while he was away on a mission. This could lead to a heartbroken Harry who questions his self - worth and his relationships. In the fanfiction, he might start to distance himself from the Weasley family as a whole, and then through a series of events, like an encounter with a wise old wizard in a forgotten corner of Hogwarts, he starts to heal and realize that he can move forward on his own path.
There's a fanfiction where Aang is heartbroken after a big battle. His friends don't fully understand his pain at first. The story focuses on how he copes with this heartbreak alone and then gradually opens up. It shows his growth from the experience. I can't recall the exact title though.
Betrayal is also a frequent theme. For example, if someone he trusts reveals his identity or uses his feelings against him, leading to his heartbreak. And then there's the theme of self - doubt. After a heartbreak, he may question whether he can still be a good hero, if his personal life is in such turmoil.
One possible reason could be unrequited love. Maybe Naruto has deep feelings for Anko, but she doesn't feel the same way. She might be focused on other things like her ninja duties or she could have feelings for someone else. Another reason could be that Anko betrays Naruto's trust in some way. For example, she might break a promise she made to him that was really important. It could also be that Anko does something that goes against Naruto's ideals, which makes him feel heartbroken as he had a different image of her in his mind.
First, understand Harry's character. Know his strengths, like his loyalty and courage, and his weaknesses, such as his self - doubt. Then, create a situation that would truly break his heart. It could be a betrayal from a close friend or the loss of someone he loves. Next, describe his emotions vividly. Show his pain through his actions, like not eating, losing sleep, or avoiding people. Also, add in some internal monologue to let the readers really get into his head. For example, 'Harry stared at the empty chair where Sirius used to sit, his heart feeling like it had been ripped out. He thought to himself, how could he go on without him?'
If Sakura were to give Naruto a token made of sakura leaves as a symbol of their friendship, and then later break off all contact with him and leave the village, Naruto would be heartbroken every time he saw a sakura leaf. The once - positive association would become a painful reminder.
One possible fanfiction could be that Sakura, in a moment of great sacrifice, uses her chakra to turn into sakura leaves that Naruto has always associated with her beauty and kindness. But this transformation is a final goodbye as she is sacrificing herself to save the village. Naruto is heartbroken as he watches the sakura leaves scatter, feeling like he has lost a part of himself.